Pure red cell aplasia (PRCA) Anemia, reticulocytopenia, absent red cell precursors in bone marrow Congenital –Diamond Blackfan anemia Acquired –Transient (parvovirus B19 in patients with hemolytic anemia) –Paraneoplasatic (thymoma, CLL) –SLE, rheumatoid arthritis –Pregnancy –Drugs – new entity: anti EPO antibodies PRCA!
Paroxysmal nocturnal hemoglobinuria (PNH) Acquired mutation in PIG-A gene occurs at the stem cell level Results in reduced/absent GPI-linked cell surface membrane proteins (CD 55, CD 59) Red cells have enhanced sensitivity to circulating complement Bone marrow failure, hemolysis and thrombosis occur
EXTRACORPUSCULAR CAUSES Immune hemolytic anemia Autoantibodies of IgG or IgM subtype IgG reacts best at 37 C = “warm” antibody Ig M reacts below body temperature = “cold” antibody
WARM AUTOIMMUNE HEMOLYTIC ANEMIA DIAGNOSTIC TEST Direct Coombs test presence of antibody (or complement) on RED CELLS Indirect Coombs test presence of antibody in SERUM
DIRECT COOMBS TEST Anti Human Globulin
Making the diagnosis in our patient Reticulocyte count –Beware… sometimes AIHA can occur without reticulocytosis!! Biochemical parameters –LDH, indirect bilirubin, haptoglobin Direct Coombs test –Indirect Coombs less informative Bone marrow biopsy –Presence or absence of red cell precursors